java - Inherit model with different JSON property names

Question

I have a class, let's say Person, that I want to populate from JSON using Jackson, but the property names vary by source. Here's how the code looks currently:

class Person {
    protected String firstName;
    protected String lastName;
    protected String address;

    public abstract void setFirstName(String firstName);
    public abstract void setLastName(String lastName);
    public abstract void setAddress(String address);

    // getters etc.
}

class PersonFormat1 extends Person {
    @Override
    @JsonProperty("firstName")
    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    @Override
    @JsonProperty("lastName")
    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    @Override("address")
    public void setAddress(String address) {
        this.address = address;
    }
}

class PersonFormat2 extends Person {
    @Override
    @JsonProperty("fName")
    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    @Override
    @JsonProperty("lName")
    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    @Override("addr")
    public void setAddress(String address) {
        this.address = address;
    }
}

As you can see, PersonFormat1 and PersonFormat2 are identical in structure, but I need different subclasses in order to specify different property names.

Is there some way to enforce the model without the boilerplate of having to redeclare and reimplement each method?

Answer 1

One way is to use PropertyNamingStrategy http://wiki.fasterxml.com/PropertyNamingStrategy

Here is nice simple demo how you can use it Link to How to Use PropertyNamingStrategy in Jackson

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The other is use MixInAnnotations http://wiki.fasterxml.com/JacksonMixInAnnotations

with MixInAnnotations you can create just one Person class and Mixin for any other alternative property name setup.

public static void main(String[] args) throws IOException {
    ObjectMapper mapper1 = new ObjectMapper();
    String person1 = "{"firstName":null,"lastName":null,"address":null}";
    Person deserialized1 = mapper1.readValue(person1,Person.class);

    ObjectMapper mapper2 = new ObjectMapper();
    mapper2.addMixIn(Person.class, PersonMixin.class);
    String person2 = "{"fName":null,"lName":null,"addr":null}";
    Person deserialized2 = mapper2.readValue(person2,Person.class);
}

public static class Person {
    @JsonProperty("firstName")
    String firstName;
    @JsonProperty("lastName")
    String lastName;
    @JsonProperty("address")
    String address;

}

public class PersonMixin {
    @JsonProperty("fName")
    String firstName;
    @JsonProperty("lName")
    String lastName;
    @JsonProperty("addr")
    String address;
}